sketch planes

hey everyone. I'm trying to build a V-shaped aircraft tail part for a glider I'm working on. You can see here: I have the basic tube extension modelled: https://cad.onshape.com/documents/916f1fc74719787d4d162627/w/b3aea26d2ea1aa3520f58285/e/3e6a0bc6f9638cb65c43fdbb But I'm having trouble figuring out how I make two sketch…